Half to geoege f



(No Model.)

0. L. INGALLS. LAMP GHIMNE Y.

Patented Apr. 10. 1888.

NITED STATES PATENT OFFICE.

CHARLES L. INGALLS, OF LOWELL, MASSACHUSETTS, ASSIGNOR OF ONE- HALF TO GEORGE F. BLAIR, OF SAME PLACE.

LAMP=CHIMNEY.

SPECIFICATION forming part of Letters Patent No. 380,801, dated April 10, 1888.

Application filed June 26, 1885. Serial No. 169,819. (No model.)

To aZZ whom it may concern:

Be it known that I, CHARLns L. INGALLS, ofLowell, in the county of Middlesex and State of Massach nsetts,a citizen of the United States, have invented a new and useful Improvement in LampChinmeys, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification, in explaining its nature.

It is well known that lampchimneys are liable to be broken in use because of the rapid variation in temperature to which they are subjected, the glass being often highly heated, and while thus heated if subjected to the infiuence of cold it cracks.

The object of my invention is, primarily, to prevent this breakage. It further, however, improves the light-giving qualities ofthe lamp to which the improvement is applied.

In the drawings, Figure l is a view in elevation showing the features of my invention. Fig. 2 is a View in plan of the spring-clamp.

Referring to the drawings, A represents the burner; B, the chimney; C, the flame of the lamp; D, the flue formed by the tube, pipe, or casing (Z, which I prefer shall be shaped into a bell-mouth, arranged immediately above the burner and at a proper height therefrom. The caliber of this flue (I must be such as to eliiciently carry off the products of combustion, and must be so much smaller than the caliber of the chimney as to leave a consider able space for the passage of air down the chimney from the outside of this flue D. The material of which this fine D is made should be such as would be comparatively refractory under the heat to which it is exposed. It would be ordinarily ofsheet metal or asbestus board.

The flue is supported within the chimney by means of arms F, which are secured to the tube or pipe d, and have at their lower ends semicircular jawsfiwhich shut upon or clasp the base of the burner. These arms are preferably spring-arms, and are adapted to clasp the burner firmly enough to prevent the oscillation of the flue in moving the lamp. The

presence of this interior flue establishes a downward draft within the chimney, and keeps thereby the glass comparatively cool, so that one cause of breakage-11ame1y, the great difference in the temperature between the inter nal and external surfaces of the glass when a current of cold air strikes upon the glassis to a great extent eliminated.

I have also ascertained that a better light is produced where this auxiliary fine is employed than where the chimney is used without it.

The lower portion of the fine should be large enough for the widest flame desired, as there will be a tendency in the flame to be somewhat narrowed on account of the concentration of the draft toward the center of the chimney, and this of course prevents to some extent the irregularjets of fiame,cansed by bad trimming of the wick,from infringing upon the walls of the chimney and thereby breaking it.

I am aware of Patents No. 70,935, to Addi son; No. 40,820, to Albertson; No. 230,466, to Butcher; No. 307,406, to Miller; No. 112,446, to Griswold, and No. 161,339, to Johnson; but while each describesalamp-chimney with some sort of a tube arranged in connection with it, neither of them shows a sub-caliber tube having a bell-shaped bottom and imperforate wall arranged within a lamp-chimney and projecting well above it, all of which characteristics I have found essential in order to get the best results, which I have described,whereby more and better light is got from the same oil and less chimneys are broken than before.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States- The combination, with a lamp burner and chimney, of a bell-mouth fine or tube extending above the top of the chimney and a support for the same, said support being composed of elastic wires, twisted as shown, the ends being formed into a spring-clamp, f, adapted to clasp the cone of the burner.

CHARLES L. INGALLS. Witnesses:

F. F. RAYMOND, 2d, GEORGE F. BLAIR. 

